Why have we used the 220-ohm Resistor?
The Arduino Digital PINS (PIN 8 in our case) will give an output of 5 volts. Now, there can be an LED whose operating voltage is 2 Volts (any lower than 5 volts), in that case, the LED may burn out.
So, we have used the resistor to supply less voltage to the LED.
Can the project be done without using the Bread Board?
Yes. But, it is always a good practice to use the Bread Board, so that you get used to with complicated projects.
Can we use a different color LED?
Of course Yes!
Why Digital Pins are used?
Since we require either HIGH or LOW voltage for Blinking LED Project.
Which Arduino Board is recommended?
Any Arduino Board you can use.
Can I use any GND Pin available on the Arduino Board?
Yes!
Can I connect a DC motor in the place of the LED?
You can, but you should not. The DC motor has very low resistance and it will try to draw more current from the Arduino Board and may burn the Arduino itself.
To use any component which requires more current, different hardware device drivers are used.